UW-Madison/Extension Plant Disease Diagnostic Clinic (PDDC) Update

Brian Hudelson, Sean Toporek, Jake Kurczewski and Ann Joy

The PDDC receives samples of many plant and soil samples from around the state. The following diseases/disorders have been identified at the PDDC from July 9, 2016 through July 15, 2016.

Plant/Sample Type, Disease/Disorder, Pathogen, County

Field Crops
Corn, Common Rust, Puccinia sorghi, Grant, Rock
Corn, Northern Corn Leaf Blight, Exserohilum turcicum, Grant Rock
Soybean, Brown Spot, Septoria glycines, Columbia
Soybean, Iron/ Manganese Deficiency, None, Sauk
Oats, Read Leaf, Barley yellow dwarf virus, Langlade

Forage Crops
Alfalfa, Lepto Leaf Spot, Leptosphaerulina briosiana, Columbia

Fruit Crops
Apple, Black Rot, Sphaeropsis sp., Trempealeau
Apple, Cedar-Apple Rust, Gymnosporangium sp., Grant
Strawberry, Root/Crown Rot, Pythium sp., Rhizoctonia sp., Bayfield, Columbia

Vegetable Crops
Garlic, Cucumber Mosaic, Cucumber mosaic virus, Waukesha
Garlic, Fusarium Basal Plate Rot, Fusarium sp., Vernon, Waukesha
Garlic, Garlic Mosaic, Unidentified potyvirus, Vernon
Garlic, Stem and Bulb nematode, Ditylenchus dipsaci, Vernon
Onion, Downy Mildew, Peronospora destructor, Rock
Onion, Purple Blotch, Alternaria porri, Rock
Onion Stemphylium Leaf Blight, Stemphylium sp., Rock
Potato, Potato Early Dying, Verticillium sp., Adams
Squash (Winter), Angular Leaf Spot, Pseudomonas syringae pv. lachrymans, Rock
Tomato, Herbicide Damage, None, Portage
Tomato, Septoria Leaf Spot, Septoria lycopersici, Portage

For additional information on plant diseases and their control, visit the PDDC website at pddc.wisc.edu.